In the following, a background art of convexo concave amplifying device and convexo concave detecting method using it, deformation sensing device and convexo concave detecting method using it, and convexo concave position exhibiting device and convexo concave position exhibiting method will be explained.
1. Convexo Concave Amplifying Device and Convexo Concave Detecting Method by Use Thereof
In a field of a tactile substitution and an artificial reality, many studies have been made for exhibiting an artificial feeling for human. For example, a tactile sensing exhibiting system whose sensing portion and displaying portion are disposed on the two sides thereof has been developed. An optical sensor reading a printed matter and a touch sensor are disposed as the sensing portion. For the displaying portion, a method of exhibiting the artificial tactile sensing by electrically stimulating a tactile receptor is adapted. Thus, this tactile sensing exhibiting system can exhibit the feeling of touching the thing which the user can not feel by himself.
However, the resolution and the sensitivity of the sensing portion and the displaying portion are insufficient. Also, the tactile sensing exhibiting system using a complex mechatronics technique is apt to invite trouble due to the complex structure. Thus, much time and labor are required for the maintenance. Further, sensing portion and the display portion can hardly be downsized.
U.S. Pat. Nos. 4,657,021 and 4,793,354 disclose means for easily detecting or sensing the convexo concave of the object. The detecting means is a touch enhancing pad comprised of two flexible sheets, and small amount of lubricant oil sealed between the two sheets. In using the touch enhancing pad, with one sheet being contacted and rested on a surface of a subject, the other sheet in contact with the finger is moved together with the finger.
As a result, movement of the lubricant oil reduces influence of friction between the subject and the fingertip, whereby the convexo concave of object can be clearly detected by smooth moving of the finger-tip. This touch enhancing pad has been put into the market by the name of “BSE (Breast Self-Examination) Pad”, and is approved by FDA as a self-examination assisting tool for the breast cancer.
Generally, the tactile sensing of the finger may get dull on the condition that some intervening material is interposed between the surface of the object and the finger tip. This pad can, without using the complex mechatronics technique, detect the object convexo concave clearly. However, it can hardly detect the small or fine convexo concave, and is not practical as the tool to detect the convexo concave of the object extensively. Further, though it has a simple construction that the lubricant oil is sealed between the two sheets, it is afraided that the lubricant oil is leaked by the damage of the sheet.
The technique for detecting the convexo concave of the object has been required in many field. In the convexo concave detecting method, the subject (surface of the object) has been inspected by contacting for example a dialogue type sensor (contact type), or by an image processing (non-contact type). However, the former type is not suitable for the extensive inspection of the object. The latter type suffers from dispersion of the detected result due to luster and blot existed on the surface of the object. Further, the both types requires expensive apparatus and much time for setting.
Therefore, in the strain inspection of a steel plate of manufacturing process in practice, for example, vehicle manufacturing process, skilled workers detect the convexo concave by the hand. However, difference in degree of skill brings different result of the detection. In addition, long period is required for the workers to acquire the skill of detecting the convexo concave. For this reason, the detecting method which can be carried out cheaply and which can detect the convexo concave easily has been required.
2. Deformation Sensing Device and Convexo Concave Detecting Method by Use Thereof
In these days, there have been many social problems such as extremely small birth rate, aging and medical care. The numbers of persons supporting a welfare service and an infrastructure may become short in the future. For this reason, a human-type robot (humanoid) which moves and reacts in the same way as the human may be required in the society. In order not to harm the person, the human-type robot needs to be covered by an artificial skin made of a soft material. Also, the artificial skin needs to have a tactile sensing function equivalent to the human skin, for example the functions to sense contact with the object and property of the object.
For realizing such function, the artificial skin in which a strain sensing elements such as a strain gauge or PVDF (polyvinylidene fluoride) sensor is embedded into the flexible material such a rubber etc. have been developed and used. However, due to poor or small elasticity and flexibility, the strain sensing element disposed in the flexible material may be broken by the stress concentration thereof. The strain sensing element and the flexible material may be peeled, or the flexible material may be cracked. In addition, since the strain gauge or the PVDF sensor has the limit of detection range, it is difficult to use them combined with the flexible material.
A tactile sensing sheet using a pressure sensitive rubber which can sense the stress acting in the normal direction thereof has been known. It however can not sense the stress acting in the tangential direction (shearing stress)
For example, Japanese unexamined patent publication H05-5397 has disclosed an external force measuring apparatus of shield excavator comprising a load detecting portion and a pressure receiving plate. One end of the load detecting portion is fixed to a bottom plate of a concave portion, and a strain gauge is mounted on the load detecting portion. The pressure receiving plate is fixed to the other end of the load detecting portion.
In this external force measuring apparatus, the external force received by the pressure receiving plate is transmitted to the strain gauge of the load detecting portion to be measured. However, if the both ends of the load detecting portion are fixed, there is a possibility that the strain gauge is broken by that the load detecting portion distorts largely. For this reason, applying the construction of H05-5397 to the flexible material can not overcome the breakage of strain gauge. Larger strain of the load detecting portion may surpass the detection range of the strain gauge.
3. Convexo Concave Position Exhibiting Device and Convexo Concave Position Exhibiting Method
As mentioned above, in the manufacturing process in practice, the skilled worker detects the convexo concave on the surface. The method of easily detecting the convexo concave and easily finding out the position of the convexo concave has been required.
With regard to exhibiting the result from detecting the surface information of the object by several sensors, for example, an invisible convexo concave on the surface of the steel plate, it is general to display the image-processed result from sensing the surface information by a detecting member (c.f. Japanese unexamined patent publication 2001-153811).
However, in order to exhibit the detected position by displaying the surface information detected by the detecting member, the position where the detecting member is detecting is needed to be measured by using a magnetic sensor, a passive linkage system, a CCD camera, and so on. Therefore, the detecting apparatus becomes large, requires a large installation space, and has a difficulty in transporting.
Instead of displaying, sounding may be used for exhibiting that the sensor detects the information on the predetermined condition. However, it is difficult to find out the detected position at the moment of sounding in the case that the surface of the object is extensively sensed with time.